1. Field of the Invention
The present invention relates to an periphery monitoring device for a motor vehicle (hereinafter referred to as xe2x80x9cin-vehicle periphery monitoring device) and a recording medium containing a program for determining danger of collision for the vehicle. More particularly, the present invention relates to an in-vehicle periphery monitoring device for monitoring an object such as a walker or bicycle on the periphery of the motor vehicle to assist assertion of safety by a driver, and a recording medium containing a processing program for determining the danger of collision between the vehicle and the object by means of a computer.
2. Description of the Related Art
While a driver operates a motor vehicle or car, there is a range out of his filed of view on the periphery of the motor vehicle even if his filed of view is supplemented by a fender mirror or back mirror. Particularly, when he operates a large car such as a truck or bus, he has a wider blind spot. Therefore, for example, when the vehicle having a right handle turns left, the driver cannot find a low object passing by the vehicle such a s a child walking along a sidewalk toward the vehicle, thus leading to an accident or catching or cutting off him. In order to obviate such difficulty, an in-vehicle periphery monitoring device has been proposed which can insure the side field of view using the side image acquired by the camera mounted on a large vehicle such as a bus to carry out the periphery monitoring in turning right or left.
However, when the driver uses the in-vehicle periphery monitoring device, he must eye the display device to make assertion of safety, which is dangerous in the assertion of safety. In order to avoid such danger, the following cutting-off accident preventing device has been proposed. The cutting-off accident preventing device decides whether or not there is an object within a prescribed area in the vicinity of the vehicle on the basis of the image picked up by a camera attached to the side of the vehicle. If xe2x80x9cYESxe2x80x9d, when a handle operation or winker operation is carried out, the cutting-off accident preventing device gives a warning that there is possibility of cutting off the object. This cutting-off accident preventing device makes it unnecessary to verify safety by eyeing and informs the danger of cutting-off by the warning, thereby improving the safety during driving.
Meanwhile, where the object moves like a walker or bicycle, even if there is the object in vicinity of the vehicle, if it moves in the direction leaving from the vehicle, as the case may be, there is no possibility of contact of the vehicle with the object. Conversely, even if there is no object in the vicinity of the vehicle, if the object moves in the direction of approaching the vehicle, there is strong possibility of collision between the vehicle and the object. Namely, the danger of collision between the vehicle and the object does not necessarily depend on only the distance between the vehicle and the object.
However, the above cutting-off accident preventing device only decides the danger of cutting-off or collision in turning left or right according to whether or not there is the object within the prescribed region in the vicinity of the vehicle, and cannot detect the danger of collision accurately.
In view of the problems as described above, a primary object of the present invention is to provide an in-vehicle periphery monitoring device which can decide the danger of collision between a vehicle and an object on the basis of the relative movements of the vehicle and object.
Another object of the invention is to provide a recording medium containing a processing program for properly deciding the danger of collision between the vehicle and the object.
In order to attain the first object, in accordance with the invention, as seen from the basic structural diagram of FIG. 1, there is provided a periphery monitoring device for a vehicle comprising: object position detecting means 51a for detecting positions of an object on the periphery of a vehicle at prescribed time intervals; expected object locus computing means 51b for computing an expected locus of the object on the basis of the positions of the object detected by the object position detecting means; expected vehicle locus computing means 51c for computing an expected locus of the vehicle; and danger determining means 51d for determining whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle.
In this configuration, since it is determined whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle, the danger can be determined accurately.
Preferably, the periphery monitoring device for a vehicle, further comprises: means for detecting a speed of the object; and means for detecting a speed of the vehicle, wherein the danger determining means determines whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected position of the object computed on the basis of the expected locus and speed of the object and the expected position of the vehicle computed on the basis of the expected locus and speed of the vehicle.
In this configuration, since the danger is determined on the basis of the speed of each of the object and vehicle as well as the loci thereof, the danger can be determined more accurately.
In accordance with this invention, there is provided a periphery monitoring apparatus for a vehicle comprising: object position detecting means having an in-vehicle monitoring means for monitoring the periphery of a vehicle to produce a monitoring signal representative of an environmental condition, the object position detecting means for detecting the positions of an object on coordinates set with respect to the position and monitoring direction of the monitoring means at prescribed time intervals on the basis of the monitoring signal; movement quantity detecting means for detecting the position and movement quantity of the monitoring means in the monitoring direction which moves for a prescribed time while the vehicle moves; expected object locus computing means for computing a real locus of the object on the basis of the positions of the object and the movement quantity of the monitoring means and computing an expected locus of the object on the basis of the real locus of the object; expected vehicle locus computing means for computing an expected locus of the vehicle; and danger determining means for determining whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle.
In this configuration, since it is determined whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle, the danger can be determined accurately.
In the periphery monitoring apparatus for a vehicle, preferably, the monitoring means is an image pick-up means which produces a plurality of image signals which are obtained by picking up the periphery of the vehicle from two positions apart from each other by a prescribed distance, and the object position detecting means detects the positions of the object on the basis of the plurality of image signals produced from the image pick-up means.
In this configuration, since the image pick-up means monitors the object within a wider range which can be picked up, the danger of collision can be determined more accurately.
It is preferred in the periphery monitoring apparatus for a vehicle that the object position detecting means detects each of a plurality of objects on the coordinates when they are picked up by the image pick-up means; the expected object locus computing means distinguishably computes an expected locus of each of the objects; and danger determining means determines whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of each of the objects and the vehicle.
In this configuration, even there are a plurality of objects, the danger can be determined for each of the objects so that it can be determined more accurately.
The periphery monitoring device for a vehicle, further comprises: means for detecting a speed of the object on the basis of the real locus of the object; and means for detecting a speed of the vehicle, wherein the danger determining means determines whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected position of the object computed on the basis of the expected locus and speed of the object and the expected position of the vehicle computed on the basis of the expected locus and speed of the vehicle.
In this configuration, since the danger is determined on the basis of the speed of each of the object and vehicle as well as the loci thereof, the danger can be determined more accurately.
Preferably, the periphery monitoring apparatus for a vehicle further comprises waning means for issuing a warning when the danger determining means determines that there is a danger.
In this configuration, a driver is beforehand informed of the danger of collision.
The periphery monitoring apparatus for a vehicle, further comprises: collision expected time computing means for computing an expected collision time on the basis of the expected position of the object and the expected position of the vehicle when the danger determining means determines that there is a danger; and warning issuing means for issuing multi-step warnings according to the collision expected time.
In this configuration, the driver can be beforehand informed of the degree of danger of collision.
In accordance with the second aspect of the invention, there is provided a recording medium containing a processing program for determining a danger of collision of a vehicle and an object by a computer, the processing program to be executed by the comprising the steps of: detecting positions of an object on the periphery of a vehicle at prescribed time intervals; computing an expected locus of the object on the basis of the positions of the object detected by the object position detecting means; computing an expected locus of the vehicle; and determining whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle. Further, there is provided a recording medium containing a processing program for determining a danger of collision of a vehicle and an object by a computer, the processing program to be executed by the computer comprising the steps of: acquiring a monitoring signal representative of an environmental condition produced from an in-vehicle monitoring means for monitoring the periphery of a vehicle; detecting the positions of an object on coordinates at prescribed time intervals on the basis of the monitoring signal; detecting the position and movement quantity of the monitoring means in a monitoring direction which moves for a prescribed time while the vehicle moves; computing a real locus of the object on the basis of the positions of the object and the movement quantity of the monitoring means; computing an expected locus of the object on the basis of the real locus of the object; computing an expected locus of the vehicle; and determining whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle.
In these configurations according to this aspect, since it is determined whether or not there is a danger of collision between the object and the vehicle on the basis of both the expected loci of the object and the vehicle, the danger can be determined accurately.